Recently, with the improvement of electronic technology, a great variety of portable electronic devices have been developed, including USB flash drives, wireless network transceivers, wireless mouse transceivers, and USB keys, to name only a few. These portable electronic devices typically have a plug to be directly inserted into an electronic apparatus (e.g., a personal computer or a laptop computer) so that the electronic apparatus can transfer data to and from the portable electronic device or execute specific functions (e.g., receiving network signals) via the portable electronic device. However, as the electronic apparatus may have several sockets configured for such plug insertion, and the sockets are usually grouped together in such a way that a plurality of portable electronic devices cannot connect to the electronic apparatus without obstructing each other, it is extremely difficult to make multiple plug connections at the same time. If it is necessary to make such connections, additional connection cables are required to position the multiple portable electronic devices in an offset relationship, which is rather inconvenient.
As a solution to the aforesaid problem, a portable electronic device with a rotatable plug was designed, wherein the plug can be freely rotated to adjust the position of the portable electronic device in the connected state. Referring to FIG. 1, a portable electronic device 1 of this kind includes a housing 11, a pivotal element 12, and a plug 13. The housing 11 is composed of a first housing member 111 and a second housing member 112. Once the first housing member 111 and the second housing member 112 are put together to form the housing 11, an accommodating space S1 and a receiving groove S2 are defined therein. A circuit element (not shown) is accommodated in the accommodating space S1, and a pivot seat 110 having a spherical interior space is received in the receiving groove S2. The pivotal element 12 is pivotally provided at one end of the plug 13 and corresponds in configuration to the interior space of the pivot seat 110 so as to rotate freely therein. The pivotal element 12 is also connected with a transmission line 14. The transmission line 14 extends out of the pivot seat 110 to make electrical connection with the circuit element. With the pivotal element 12 pivotally connected to the pivot seat 110, the plug 13 can rotate along with the pivotal element 12 until the plug 13 is received in the receiving groove S2 or secured outside the housing 11 at a position corresponding to the receiving groove S2.
While the plug 13 of the portable electronic device 1 is freely rotatable and adjustable by the user and can be conveniently received in the receiving groove S2, it still has the following drawbacks in use:
(1) Difficulty in rotation: Referring to FIG. 1, the transmission line 14, which extends out of the pivot seat 110 to electrically connect with the circuit element, will be pulled by the plug 13 or even curled along the pivot seat 110 when the plug 13 is rotated. Consequently, not only is the transmission line 14 subject to wear and tear, but also the smoothness of rotation of the plug 13 is impaired, which hinders the use of the plug 13.
(2) Limited rotation: As stated above, the transmission line 14 tends to be pulled or curled when the plug 13 is turned. Therefore, the extent to which the plug 13 can be rotated is limited by the length of the transmission line 14. If the plug 13 cannot be sufficiently rotated, it may have problem avoiding physical contact between the portable electronic device 1 and an adjacent portable electronic device.
(3) An excessively large space occupied: In order for the pivotal element 12 to rotate freely in the pivot seat 110, the interior space of the pivot seat 110 must be spherical, and because of that, the pivot seat 110 and the pivotal element 12 occupy a very large space, which is against the trend of portable electronic devices toward increasingly smaller and slimmer designs. Moreover, as previously mentioned, the transmission line 14 of the portable electronic device 1 must be long enough to allow smooth rotation of the plug 13. This long transmission line 14 nevertheless adds to the overall volume of the portable electronic device 1.
(4) Insufficient structural strength: Referring again to FIG. 1, there is a partition 113 between the receiving groove S2 and the accommodating space S1 so that the plug 13, once received in the receiving groove S2, is pressed against the partition 113 to give the user an assuring feel that the plug 13 is stored in place. However, given the trend toward making the portable electronic device 1 as compact as possible, the thickness of the partition 113 is often limited. As a result, the partition 113 tends to deform due to the pressing force of the plug 13 after the portable electronic device 1 is used for a long time.
According to the foregoing, the rotatable plug of a conventional portable electronic device cannot rotate without pulling or curling the transmission line and therefore suffers from difficulty and limitation in rotation. The rotatable plug also results in bulkiness of the portable electronic device. Hence, the issue to be addressed by the present invention is to design a portable electronic device and provide it with a rotatable plug that will not pull or curl the transmission line when in use or have the other problems mentioned above.